This invention relates to a wood type of golf clubhead. More particularly the invention relates to a golf clubhead which has a recessed or inverted hosel portion, an alignment groove for aligning the clubhead, a flat sole portion, and an aerodynamic shape.
Golf clubs of the wood type are no longer made only from wood. Such clubs are now commonly made from metal such as stainless steel, titanium, and aluminum and from composite material such as fibers of graphite, Kevlar.TM., or boron and resin.
Many golf clubheads include a hosel which extends upwardly above the face of the clubhead for attaching the shaft of the clubhead. However, a conventional hosel increases weight in the high heel area. It is becoming increasingly common for golf club designers to redistribute the weight of the clubhead to the high toe and low heel areas as taught, for example, by U.S. Pat. Nos. 4,471,961 and 5,120,062.
Some clubheads have used a shorter hosel to reduce weight in the high heel area. For example, U.S. Pat. Nos. 5,042,806 and 5,240,252 describe clubheads in which the hosel does not extend above the face. However, such a clubhead does not provide the same support for the shaft as does a clubhead with a traditional hosel.
Another problem with wood type clubheads is properly aligning the face of the clubhead. With iron type clubheads many golfers use the bottom groove of the face to align the clubhead square, i.e., perpendicular, to the intended line of flight. The top line of an iron clubhead cannot be used to align the clubhead because the top line is not perpendicular to the intended line of flight as viewed by a golfer at address.
However, the face of a wood type golf club has a low loft angle, and the grooves of the face are not easily apparent and usable for alignment at address. Using the face grooves for alignment is also complicated by the fact that the face of most wood type clubheads is provided with bulge and roll curvature, as explained, for example, in U.S. Pat. No. 4,471,961.
Many wood type golf clubs therefore include some alignment indicator such as a line or arrow on the top of the clubhead which indicates the intended line of flight. However, some golfers prefer to use the face for aligning the clubhead square rather than relying on an indicator on top of the clubhead.